environs/ec2: define names for columns in images file
environs/ec2: define names for columns in images file

R=niemeyer
CC=
https://codereview.appspot.com/6220065

bz2/juju,marcmolla/juju,gabriel-samfira/juju,bz2/juju,AdamIsrael/juju,frobware/juju,ericsnowcurrently/juju,bz2/juju,davecheney/juju,cherylj/juju,voidspace/juju,mhilton/juju-juju,howbazaar/juju,macgreagoir/juju,mikemccracken/juju,marcoceppi/juju,makyo/juju,makyo/juju,tsakas/juju,alesstimec/juju,waigani/juju,kat-co/juju,mikemccracken/juju,mattyw/juju,axw/juju,frankban/juju,tych0/juju,frankban/juju,mikemccracken/juju,dimitern/juju,frankban/juju-tmp,bac/juju,axw/juju,mattyw/juju,marcmolla/juju,AdamIsrael/juju,reedobrien/juju,Altoros/juju-vmware,marcoceppi/juju,Altoros/juju-vmware,kat-co/juju,mhilton/juju,tych0/juju,cherylj/juju,cloud-green/juju,marcmolla/juju,alesstimec/juju,bogdanteleaga/juju,cmars/juju,reedobrien/juju,alesstimec/juju,frankban/juju,voidspace/juju,fwereade/juju,gabriel-samfira/juju,Altoros/juju-cloudsigma,Altoros/juju-cloudsigma,rogpeppe/juju,macgreagoir/juju,gabriel-samfira/juju,macgreagoir/juju,makyo/juju,perrito666/juju,anastasiamac/juju,mikemccracken/juju,mjs/juju,mhilton/juju,tsakas/juju,davecheney/juju,sinzui/juju,sinzui/juju,wwitzel3/juju,perrito666/juju,axw/juju,anastasiamac/juju,wwitzel3/juju,dimitern/juju,mhilton/juju-juju,mhilton/juju-juju,waigani/juju,fwereade/juju,cmars/juju,thomnico/juju,dooferlad/juju,howbazaar/juju,howbazaar/juju,tasdomas/juju,dooferlad/juju,dooferlad/juju,frankban/juju,dooferlad/juju,makyo/juju,tych0/juju,jrwren/juju,AdamIsrael/juju,reedobrien/juju,cherylj/juju,bogdanteleaga/juju,alesstimec/juju,davecheney/juju,bac/juju,howbazaar/juju,waigani/juju,tasdomas/juju,bz2/juju,rogpeppe/juju,Altoros/juju-cloudsigma,kat-co/juju,alesstimec/juju,anastasiamac/juju,cloud-green/juju,frankban/juju-tmp,voidspace/juju,frankban/juju,reedobrien/juju,tych0/juju,wwitzel3/juju,rogpeppe/juju,frankban/juju-tmp,sinzui/juju,Altoros/juju-cloudsigma,sinzui/juju,bz2/juju,kat-co/juju,mjs/juju,thomnico/juju,frobware/juju,thomnico/juju,frankban/juju-tmp,mjs/juju,macgreagoir/juju,anastasiamac/juju,macgreagoir/juju,mikemccracken/juju,marcoceppi/juju,marcoceppi/juju,mjs/juju,wwitzel3/juju,bogdanteleaga/juju,tsakas/juju,bogdanteleaga/juju,thomnico/juju,cloud-green/juju,frobware/juju,dooferlad/juju,perrito666/juju,perrito666/juju,fwereade/juju,Altoros/juju-vmware,perrito666/juju,gabriel-samfira/juju,anastasiamac/juju,ericsnowcurrently/juju,ericsnowcurrently/juju,mhilton/juju,cherylj/juju,marcmolla/juju,bac/juju,davecheney/juju,mjs/juju,tasdomas/juju,tasdomas/juju,AdamIsrael/juju,jrwren/juju,cloud-green/juju,fwereade/juju,howbazaar/juju,dimitern/juju,tsakas/juju,jrwren/juju,mattyw/juju,kat-co/juju,waigani/juju,dimitern/juju,ericsnowcurrently/juju,mhilton/juju-juju,mattyw/juju,ericsnowcurrently/juju,reedobrien/store,axw/juju,bac/juju,reedobrien/juju,axw/juju,dimitern/juju,gabriel-samfira/juju,mjs/juju,mjs/juju,marcmolla/juju,Altoros/juju-vmware,mhilton/juju,cmars/juju,cmars/juju,bac/juju,voidspace/juju